Pie Chart - Important Points
Pie Chart
Pie chart is widely used to represent data in various reports. In data interpretation section, pie chart questions are asked in all exams. Sometimes, a data interpretation may involve a pie chart with data table.
In a pie chart, the values of different components are represented by the sectors of a circle. These sectors are so constructed that the area of each sector is proportional to the corresponding value of the component.
Pie Chart Formula
Since the sum of all the central angles is 360 degrees, we have
Central angle of a component = ((value of the component)/(total value) × 360) degrees
360 degree = 100% of value
3.6 degree = 1%
90 degree = 25%
180 degree = 50%
Pie Chart Interpretation
While interpreting pie chart, the following points should be taken into account:
- Each segment of pie represents a particular value.
- If values are given in degrees, use the above formula to convert into percentage.
- Percentage or angle values within a pie can be compared without taking into account the total value.
- Percentage or angle values from two different pies cannot be compared without knowing total values for each pie as they might be having different total values.
Example: The revenue of company under different heads (in crores of rupees) is given below:
Head |
Expenditure (in Crores) |
Raw Material |
300 |
Electricity |
100 |
Rent |
150 |
Man Power |
200 |
Miscellaneous |
250 |
This table has been converted into Pie Chart.
Pie Chart showing Expenditure of company under different heads (in crores of rupees) Total expenditure = 1000 crores
Q1: What is the difference of expenditure between rent and electricity?
Solution: Difference = 15% - 10% = 5% of 1000 = 50 crores
Q2: Expenditure on rent is how much percent more than that on electricity?
Solution: We do not have to take the actual expenditure into account.
Required % = (5x/10x) x 100 = 50%